Route notifying methods and electronic devices

Abstract

The present disclosure provides route notifying methods and electronic devices. In an embodiment, a first ASBR in a first AS carries an NLRI as well as a newly-added BIER Path Attribute in a UPDATE message and notifies them to a second AS. BIER information in the autonomous system is exchanged between the ASs in a cross-AS BIER scenario, and BIER route notifying between the ASs in the cross-AS BIER scenario is realized.

The invention claimed is: 
     
         1 . A route notifying method, the method being performed by a first autonomous system border router (ASBR) in a first autonomous system (AS), wherein the first ASBR is connected with a second ASBR in a second AS; the method comprises:
 collecting Bit-Forwarding Router (BFR) identifiers (IDs) of respective BFRs in the first AS, comprising:
 collecting a BFR ID of a BFR deployed as a Bit-Forwarding Ingress Router (BFIR) in the first AS; and 
 collecting a BFR ID of a BFR deployed as a Bit-Forwarding Egress Router (BFER) in the first AS; and 
   notifying a route UPDATE message to the second ASBR in the second AS, wherein the UPDATE message carries network layer reachability information (NLRI) and a Bit Index Explicit Replication (BIER) Path Attribute; the NLRI at least comprises a first BFR prefix of the first ASBR in a first Sub-Domain (SD); the BIER Path Attribute at least comprises the collected BFR IDs; the UPDATE message is used for a BFR in the second AS to add a corresponding Bit Index Forwarding Table (BIFT) forwarding entry in a BIFT according to the NLRI and the BIER Path Attribute; and the BIFT forwarding entry at least comprises: a BFR neighbor and a forwarding bit mask (F-BM), the BFR neighbor is indicated by the first BFR prefix, the F-BM represents BFR IDs corresponding to respective BFRs reachable via the BFR neighbor, and the BFR IDs represented by the F-BM at least comprise the BFR IDs collected by the first ASBR in the first AS.   
     
     
         2 . The method of  claim 1 , wherein the BIER Path Attribute carries a first TLV; the first TLV at least comprises at least one field pair, and each field pair comprises a BFR ID field and a BFR ID range field which are in corresponding relationship;
 the first TLV carries the BFR IDs collected by the first ASBR in the first AS through at least one field pair; wherein in each field pair, a parameter carried in the BFR ID Range field represents a BFR ID segment with continuous values, and the BFR ID field carries a start BFR ID of the BFR ID segment.   
     
     
         3 . The method of  claim 1 , wherein the BIER Path Attribute further carries a second TLV;
 a type field in the second TLV is used to carry a BIER encapsulation type supported by the first ASBR; and   the second TLV further comprises a BIER encapsulation information field which is used to carry BIER encapsulation information supported by the first ASBR; and the BIER encapsulation information is used to determine an entry identifier of the BIFT forwarding entry.   
     
     
         4 . The method of  claim 1 , wherein the BIER Path Attribute further carries an SD configuration field;
 the SD configuration field carries SD configuration information;   
       wherein the SD configuration information at least comprises the first SD and the BFR ID of the first ASBR. 
     
     
         5 . A route notifying method, the method being performed by a network device in a second autonomous system (AS) and comprising:
 when the network device is a second border router (ASBR) and the second ASBR is connected with a first ASBR in a first AS,   receiving a route UPDATE message notified by the first ASBR in the first AS, wherein the UPDATE message carries network layer reachability information (NLRI) and a Bit Index Explicit Replication (BIER) Path Attribute, the NLRI at least comprises a first Bit-Forwarding Router (BFR) prefix of the first ASBR in a first Sub-Domain (SD); the BIER Path Attribute at least comprises BFR IDs collected by the first ASBR in the first AS; wherein the collected BFR IDs comprises: a collected BFR ID of a BFR deployed as a Bit-Forwarding Ingress Router (BFIR) in the first AS, and a collected BFR ID of a BFR deployed as a Bit-Forwarding Egress Router (BFER) in the first AS; and   notifying the NLRI and the BIER Path Attribute in the second AS, so that any BFR receiving the NLRI and the BIER Path Attribute in the second AS adds a corresponding Bit Index Forwarding Table (BIFT) forwarding entry in a local BIFT.   
     
     
         6 . The method of  claim 5 , wherein when the network device is any BFR other than the second ASBR, the method further comprises:
 when receiving the NLRI and the BIER Path Attribute notified by the second ASBR in the second AS, adding a corresponding Bit Index Forwarding Table (BIFT) forwarding entry in a local BIFT; wherein the BIFT forwarding entry at least comprises a BFR neighbor and a forwarding bit mask (F-BM), the BFR neighbor is indicated by the first BFR prefix, the F-BM represents BFR IDs corresponding to respective BFRs reachable via the BFR neighbor, and the respective BFRs reachable via the BFR neighbor comprise BFRs corresponding to the BFR IDs collected by the first ASBR in the first AS.   
     
     
         7 . The method of  claim 6 , further comprising:
 when receiving an original multicast packet, forwarding an IPV6 packet corresponding to the original multicast packet to a target BFR, wherein the IPV6 packet is obtained by encapsulating BIER information and IPV6 information in the original multicast packet, the BIER information at least comprises a Bitstring, a bit in the Bitstring corresponding to a BFR ID of the target BFR is set as a first value for indicating forwarding, the BFR IDs represented by the F-BM comprise the BFR ID of the target BFR, an outer layer IPv6 destination address in the IPV6 information is the first BFR prefix.   
     
     
         8 . The method of  claim 5 , wherein when the network device is the second ASBR, the method further comprises:
 when receiving an IPV6 packet corresponding to an original multicast packet, forwarding the IPV6 packet according to an outer layer IPV6 destination address in the IPV6 packet, wherein the IPV6 packet is obtained by encapsulating BIER information and IPV6 information in the original multicast packet.   
     
     
         9 . An electronic device, comprising a processor and a machine readable storage medium;
 wherein the machine readable storage medium stores machine executable instructions executable by the processor;   the processor is configured to execute the machine executable instructions to implement a route notifying method, the method being performed by a first autonomous system border router (ASBR) in a first autonomous system (AS), wherein the first ASBR is connected with a second ASBR in a second AS; the method comprises:   collecting Bit-Forwarding Router (BFR) identifiers (IDs) of respective BFRs in the first AS, comprising:
 collecting a BFR ID of a BFR deployed as a Bit-Forwarding Ingress Router (BFIR) in the first AS; and 
 collecting a BFR ID of a BFR deployed as a Bit-Forwarding Egress Router (BFER) in the first AS; and 
   notifying a route UPDATE message to the second ASBR in the second AS, wherein the UPDATE message carries network layer reachability information (NLRI) and a Bit Index Explicit Replication (BIER) Path Attribute; the NLRI at least comprises a first BFR prefix of the first ASBR in a first Sub-Domain (SD); the BIER Path Attribute at least comprises the collected BFR IDs; the UPDATE message is used for a BFR in the second AS to add a corresponding Bit Index Forwarding Table (BIFT) forwarding entry in a BIFT according to the NLRI and the BIER Path Attribute; and the BIFT forwarding entry at least comprises: a BFR neighbor and a forwarding bit mask (F-BM), the BFR neighbor is indicated by the first BFR prefix, the F-BM represents BFR IDs corresponding to respective BFRs reachable via the BFR neighbor, and the BFR IDs represented by the F-BM at least comprise the BFR IDs collected by the first ASBR in the first AS.   
     
     
         10 . The electronic device of  claim 9 , wherein the BIER Path Attribute carries a first TLV; the first TLV at least comprises at least one field pair, and each field pair comprises a BFR ID field and a BFR ID range field which are in corresponding relationship;
 the first TLV carries the BFR IDs collected by the first ASBR in the first AS through at least one field pair; wherein in each field pair, a parameter carried in the BFR ID Range field represents a BFR ID segment with continuous values, and the BFR ID field carries a start BFR ID of the BFR ID segment.   
     
     
         11 . The electronic device of  claim 9 , wherein the BIER Path Attribute further carries a second TLV;
 a type field in the second TL V is used to carry a BIER encapsulation type supported by the first ASBR; and   the second TLV further comprises a BIER encapsulation information field which is used to carry BIER encapsulation information supported by the first ASBR; and the BIER encapsulation information is used to determine an entry identifier of the BIFT forwarding entry.   
     
     
         12 . The electronic device of  claim 9 , wherein the BIER Path Attribute further carries an SD configuration field;
 the SD configuration field carries SD configuration information;   wherein the SD configuration information at least comprises the first SD and the BFR ID of the first ASBR.   
     
     
         13 . An electronic device, comprising a processor and a machine readable storage medium;
 wherein the machine readable storage medium stores machine executable instructions executable by the processor;   the processor is configured to execute the machine executable instructions to implement the method as claimed in  claim 6 .   
     
     
         14 . The electronic device of  claim 13 , wherein when the network device is any BFR other than the second ASBR, the processor is further configured to execute the machine executable instructions to:
 when receiving the NLRI and the BIER Path Attribute notified by the second ASBR in the second AS, add a corresponding Bit Index Forwarding Table (BIFT) forwarding entry in a local BIFT; wherein the BIFT forwarding entry at least comprises a BFR neighbor and a forwarding bit mask (F-BM), the BFR neighbor is indicated by the first BFR prefix, the F-BM represents BFR IDs corresponding to respective BFRs reachable via the BFR neighbor, and the respective BFRs reachable via the BFR neighbor comprise BFRs corresponding to the BFR IDs collected by the first ASBR in the first AS.   
     
     
         15 . The electronic device of  claim 14 , wherein the processor is further configured to execute the machine executable instructions to:
 when receiving an original multicast packet, forward an IPV6 packet corresponding to the original multicast packet to a target BFR, wherein the IPV6 packet is obtained by encapsulating BIER information and IPV6 information in the original multicast packet, the BIER information at least comprises a Bitstring, a bit in the Bitstring corresponding to a BFR ID of the target BFR is set as a first value for indicating forwarding, the BFR IDs represented by the F-BM comprise the BFR ID of the target BFR, an outer layer IPV6 destination address in the IPV6 information is the first BFR prefix.   
     
     
         16 . The electronic device of  claim 9 , wherein when the network device is the second ASBR, the processor is further configured to execute the machine executable instructions to:
 when receiving an IPv6 packet corresponding to an original multicast packet, forward the IPV6 packet according to an outer layer IPV6 destination address in the IPV6 packet, wherein the IPV6 packet is obtained by encapsulating BIER information and IPV6 information in the original multicast packet.   
     
     
         17 . A non-transitory machine readable storage medium storing several computer instructions, where the computer instructions are executed by a processor to implement the method according to  claim 1 . 
     
     
         18 . A non-transitory machine readable storage medium storing several computer instructions, where the computer instructions are executed by a processor to implement the method according to  claim 5 .